1) A method is being developed for extraction and purification of protein kinases associated with rod membranes, one that phosphorylates rhodopsin with ATP and the other that phosphorylates phosvitin. 2) Three isochromic forms of rhodopsin have been separated and purified. These fcrms contain different amounts of phospholipid and demonstrate different bleaching kinetics. BIBLIOGRAPHIC REFERENCES: Shichi, H.: Molecular biology of the visual process. In Siegel, G.J., Albers, R.W., Katzman, R. and Agranoff, B.W. (eds.): Basic Neurochemistry. Boston, Little, Brown & Co., pp. 148-163, 1976. Shichi, H., Muellenberg, C.G., Harosi, F.I., and Somers, R.L.: Isolation of three isochromic forms of rhodopsin in digitonin. Vision Res. 17: 633-636, 1977.